[From the Wetpixel homepage]

Hi Gang,

"We just heard from Blake at Aquatica that they have made a breakthrough and will be offering their Canon 300D digital Rebel housing with TTL strobe control. Aquatica's electrical engineers have "cracked the TTL code" for the Canon 300D and will install special circuitry between the camera's hotshoe and the housing bulkhead which will enable the camera to communicate with underwater strobes for automatic strobe control.

One of Aquatica's beta testers is trying out the 300D housing with TTL right now in Bonaire and should have a report soon. We don't know yet which strobes will be TTL compatible with the setup, but we hope to find out soon - so check back here and on the Wetpixel homepage for more information as it becomes available."

To see some photos of the housing from our past article, click on:

http://wetpixel.com/archives/00000151.shtml

Cheers
James Wiseman

On wonders why everyone is skipping the 10D. Is the Rebel just that popular a price point? Nonetheless, with this news, and at least the possibility of INON having cracked the same code, I may yet get a DSLR in the water this year . . .

In addition to TTL the DR will fire the strobe to aid autofocus when it thinks it's needed. If this works out, it may eliminate the need for a modeling light. Of course all these short pulses may cut into the full power output of the strobe.

Blake had mentioned something along this line to me last week that made me think. Awesome.

Herb and I are feeling less and less like guinea pigs everyday.

Estimated shipping is still mid February.

In what ways could this work? Does it require a DX strobe or Ike equivalent? I don't think regular strobes recycle enough to generate preflashes.

Most strobes will not recycle fast enough, so you'll get less than full power. It can still work depending of the detail of how the Canon TTL actually operates.

I think Aquatica will have to put in a flash exposure compensation control to make this really useful since the DR does not have it. I think a large percentage of TTL shots underwater require some compensation for a proper exposure.

Are UW strobes able to do this? The S2 does not.

Hang in there Kasey,

I'm thinking (and this is my opinion only) that if Aquatica can crack eTTL then they can do Nikon also. They probably did the D-Rebel first because they think that camera will gain them a lot of market share (and I bet it will) because the camera is under $1,000

We'll have to wait for a report from Aquatica about which strobes are compatible.

I have heard that eTTL fires even more preflashed than Nikon's dTTL and that the Nikon protocol is easier to mimic - we'll have to wait and see. Plus, Nikon keeps changing theirs - now they have iTTL.

Cheers
James

Scotty,

The pop-up flash on the newer Canon DSLR's can do stroboscopic flash pulses. Canon has decided to do away with a dedicated focusing light on the camera and is using the pop flash for a focus light now. It's not a "continuous on" lamp, but it fires fast enough that it seems like it is.

Cheers
James

This is one of the most annoying features in the world, in my opinion. It makes people quite uncomfortable! Even the bright white focus-assist lamp on the D60 and 10D is pretty bad. Red of infrared (like the mid-range SLRs use) is much preferred. I can't imagine that it costs that much more to implement!

So James,
My question to you is, would you buy this setup, if you were starting from scratch?
As a closet admirer of the S2 and it's results :ph34r: I'm wondering if you feel this is a better option.
Rand

I don't fully agree, if your strobes are positioned correctly it will work every time and can be used in conjunction with aperture & shutter controls and ISO.

Nikonos type strobe fittings will almost certainly be utilised by Aquatica and consequently giving a choice of Nikonos, S&S Duo & N, Inon etc. Otherwise building the interface module was pointless. Preflash will not work with standard low technology strobes; the thyrister dischage is controled by an integral IC only found in surface dedicated units. So in reality using housed canon strobes may be a better alternative if one needs preflash.
Not sure whether S&S still do their Canon dedicated strobe anymore (YS60C).

Well Rand, that depends what your definition of "better" is. :-)

It's the best DSLR option (IMO) If you don't want to shell out >$1,000 for a camera body. And it can do just about everything that my S2 setup can do... but not everything.

Cheers
James

Maybe not every time. For some shots under some conditions, getting strobes "positioned correctly" can be difficult or impossible without compensation. For example, CFWA in low ambient light conditions requiring large apertures. Positioning poweful strobes behind the plane of the camera can solve this problem for a wide-angle scenic of a relatively close larger subject (say, a sea fan), but not for a smaller, closer main subject close to the dome (say, a frogish or leaf scorpionfish), where the strobe light will be be blocked by the housing itself, as well as the shooter's head and body.

Positioning the strobes so that the CF subject can be properly illuminated can result in over-exposure at wide apertures if the subject-strobe distance is to close and the TTL circuitry cannot shut the strobes down fast enough to ensure a correct exposure.

Obviously this problem can also be solved by using smaller, less powerful strobes, but many of us want to be able to shoot CFWA subjects without necesarily having to change the standard wide-angle equipment configuation.

For me, with both my digital and film rigs, -0.5 flash compensation seems to work
best in most situations with Ikelite SS-200s positioned conventionally, positioned on 24" arms and aimed forward, at least up to f/8. At tighter apertures, and of course for almost any macro shots, the TTL circuitry can shut down the strobes fast enough without negative flash compensation. With my back-up strobes (Sea & Sea 90 DX) similarly positioned, no negative flash compensation is ever required.

Robert Delfs

Hi Robert,

In the shooting situation you outlined (CFWA) most people would shoot manual strobes. That's what I do and recommend for that type of shot.

In that situation, flash compensation isn't required or even used by the camera.

Cheers
James

Sorry Robert I should have been more specific. I was thinking about close-up and macro. CFWA rarely if ever works using TTL the foreground would get blown out.

TTL utilising standard type UW strobes is very basic, to say the least, but it works well, albeit within tighter parameters than dedicated units like the 80DX.

Also, I don't regard this as a cheap alternative to its peers, one still has to buy housing, ports, arms, strobes, gears and there's $3-4000 gone already!

Thank you Bob, that's the point I was trying to make with James and perhaps pry some comparisons out of him regarding the two cameras. In the overall scheme of things, the camera is just another accessory.
Sure the S2 is 4 or 5 hundred more but that won't even buy a decent lens so I consider the difference minimal. In the big picture.
Of course James, if you didn't want to respond because it might compromise your affiliations with site advertisers, I understand.
Rand

What site advertisers? At the moment, none of the manufacturers explicitly advertise on this site.

This is going to change soon, but I just wanted to point that out.

Congratulations on that Eric. I didn't really know for sure and didn't want to press the point if it was going to cause a problem.
Rand

OK, well, I really "dodged" it because I don't want this to turn into a Nikon vs Canon thread...:-)

I would get the S2 again over the D-rebel and the Aquatica 300D housing. Nikon's lenses for sensors of this size are simply much better at this point in time. That may change, but today, it's the case. Good wideangle zoom, true fisheye, 70-180 macro zoom, 60mm macro does 1:1, etc.

But it's bigger, costs more, and Fuji may have the "next big thing" around the corner for a PMA announcement...

There, did that make your decision easier? Heh :-)

Cheers
James

We're going to be taking more site "sponsors" soon, but Wetpixel as a community will always stay impartial. I refuse to take sponsorship if it means that I have to censor myself or anyone officially affiliated with Wetpixel. If you see this changing, please slap me -- in the feedback forum, or via e-mail.

Actually James, yes it did. Think I'll wait and see what Fuji says. To my eye, the S2 is producing the quality of image I like. Both in sharpness and tones. How or why I don't really know. If there is an S3 anounced or whatever...I'll look at that. I get the feeling you may think I'm trying to corner you on the issue. That's not the case. But as you say, the thread isn't about a comparison so lets leave it where it is.
Rand

Bob, I'm very interested in your view on this. As you know, I've never used TTL underwater. I do remember a talk by Larry and Denise Tackett at an NCUPS meeting about a year ago where they discribed how they took some of their photos. They shoot TTL and quite a few of their shots were taken with some flash exposure compensation. That's where I learn that Nikonos shooter use the ISO setting for that purpose.

Here're a couple of examples I'd like your comment on:

This was taken with DR which has a reputation for under exposing flash photos:



Having no reflected light from the flash over a large percentage of the area fooled the TTL into over exposing.

Here's one that I think would suffer the same fate had I used TTL with no compensation.



Could that be avoided with strobe placement alone?

Very interesting thread. The Aquatica break through means I am going to have to rewrite my BSOUP talk for next week! Surely the same circuitry is needed for the 10D and D60? I can't imagine Canon used different flash protocols for each?

---

Herb, one thing I have noticed amongst my diving friends is that those with older cameras F801s F90x etc more regularly use TTL compensation (usually underexposing by 1/3 to 2/3s of a stop), than users of more modern Nikons with better flash metering. The newer Nikons have better multi-zone flash metering (not the same as matrix ambient light meter) and are able to deal with the small foreground subjects and off centre subjects. The Nik V, if I remember correctly has just a single zone TTL sensor, that doesn't even cover the whole frame that well.

I'll leave Bob to comment on the flash positioning. I love the balance of light you have achieved in the goby shot. IMO you would be able to achieve that with TTL on a Nikon F5 or F100, but would burn out the goby on a F801, F90 or Nik V.

Alex

Hong Kong looks great at night eh, but you sure looked pale!

This was my point exactly regarding blowing out the foreground, especially in AP. Without knowing your settings it's difficult to comment further. What flash were you using?

The second shot yes, TTL would have worked without compensation as the reflected light would have been enough with subject so close to the focal plane. I have the same shot (not surprisingly) but away at a magazine and unscanned; taken with TTL.
Both f. stop and strobe positioning would be important creatively, but my preset f.22 and strobe positioning covers most macro situations and is relatively unchallanging, leaving the tired remnants of my brain to juggle with composition.

Using a dedicated gun is generally more flexible allowing smaller apertures to be used. Certain program modes offer good alternatives too. My little Oly C-100 has a night shot mode which would have sorted the first shot out automatically! One of the programmable flash options on my Dynax 9's will do the same job, not sure if that is available on the DR?

Compensating by reducing output is no longer TTL as such, as it becomes flash fill which has to be balanced. I'm so used to doing these things in my head automatically, I've forgotten how to offer a practical explanation!

Example TTL shot (Nikonos V with single YS120)

f.11 @ 1/90 using 100 ASA Agfa conveyor chip.

I use 90x's now Alex, and my TTL exposures are perfect without having worried about compensation (including several whip goby & xenocrabs). I took 720 macro images in Lembeh using TTL, 688 are publishable the rest suffered from a sync lead or focusing problem (my eyes in SM).

Bob, you wasted nearly a whole roll! I think your high strike rate demonstrates what can be achieved by someone who really knows their kit.
I think photographers can often over complicate things - by dialling unnecessary compensation and fiddling with settings that work.
Alex

Yes, working it out it was almost a roll, Far less waste than a Nikonos for sure!
I'll bet it'll surprise the hell out of you to learn that I had never used this kit before... In fact it arrived in Manado in the different bags of different divers from different countries Great... but then i had to take it back to UK myself: No wonder my heart packed up

Rand I understand waiting to see what PMA has to announce on the Fiji side. But, you seem to infer that the Canon is producing less pleasing images.

I am not sure I would make that statement right now as I have only seen maybe a dozen underwater shots with this camera.

As for price difference, correct me if I am wrong but, in the Aquatica realm the housing is about $300 more for the S2, the camera is about $500 more and you are starting with no lens (a pricey add) Thus, when you add up the tally it is a bit more than $400-500 to go to the S2. I have not factored in ports as they are transferable amoung the various housings produced and a moot point in terms of price comparisons.

To a person starting from scratch in terms of lenses and DSLR that is a big factor as the credit card limit can get maxed out very fast.

On the lens front, I would expect the market that the Rebel is grabbing will produce a lens selection that will catch up to Nikon very quickly (I was betting on this fact). As for quality of lenses I am not touching that debate as I am not knowledgeable enough to comment on this area. (Recent 12-24 Sigma review may already be indicating this)

Yes, agree with most of what is said in this thread. Many of the comments about "TTL doesn't work for this type of shot" are based on experience with older systems like the 8008 and Nikonos V. Those cameras had first generation TTL systems but many of the "godfather" underwater shooters that we hear from today (Larry and Denise, etc) used them as their first UW setup.

Newer cameras have a LOT of TTL sensors, not just one. They have advanced flash modes like "3-D multi-sensor balanced fill flash" that is supposed to take into account for reflective subjects and small subjects that don't fill the frame. It just takes a bit of experience with the different cameras before you get comfortable with how the system works - but I firmly believe that it DOES work.

Oh, and don't listen to Bob - he's full of beans! He borrowed someone elses strobes on the Manado trip - and they were NOT YS90DX's!

Cheers
James

I've met several folks who use TTL for wide angle and add negative exposure compensation.

The first tip I received from a pro was to do this. Just use minus .7-2.3 exposure compensation. I never quite found out how one calculated the amount. I found using the guide number chart on the back of the SS200 much easier and just shot manual. To each his own.

It's funny. I've had little interest in any new cameras. I'm not interested in an upgrade. The D100 works fine for me. Higher end models or full frame doesn't entice me one bit. But I've decided that I would like a backup camera. Another D100 would make the most sense. But for some reason, the unknown S3 is just gnawing at me. There are a couple of things I don't like about the S2. If they get fixed, I may start drooling again for the first time in well over a year. I just hope that don't overdo it and price it out of range.

I was on about camera bodies you plonker, and I do got a 60 a 90 & a 120. You don't have to take my word for it!

I love the "plonker" line, I'll have to use that one but man I thought you were Darren there in that last post.

But, yes James Bob had borrowed some Inon strobes in Lembeh but does have his own arsenal of strobes, he wanted to have two full set-ups going. You Plonker!

Man I like that one.

It can be used as a verb, adjective, and noun!

Plonk this you plonking plonker!

Cheers
James

If the Plonk fits wear it

I've considered getting a 300d and this talk about being able to get TTL with the Aquatica housing is plonkin' great news I think. Does anyone know how much the housing will be? What port to use with the standard Rebel lens and how much could I expect to pay for that little piece of plonk?

It was posted up about a month ago, I'll have to search to find the price but it was in the $1569USD range for the housing.
Add ports

Here it is

http://wetpixel.com/forums/index.php?showt...l=digital+rebel

A little more Plonk that the 5000 but I expect to have a one Plonking good time with it.

Whoo hoo!! Guess this means that one of my predictions for 2004 came true!! Ok not "exactly" true, but close enough.

That shot from Hong Kong was taken just before dinner and I was starved.

It was shot with the DR builtin flash, on manual exposure. I think Alex's observation, the metering capabilty of the cameras determine if compensation is needed, is correct. The DR, for whatever reason, uses "Center Weighted Average" metering when manual exposure is chosen. Since there was esentailly nothing but air in the center of my shot, it was over exposed. Had I parked myself in the middle of the frame, the photo would probably be properly exposed.

The same may apply to the lionfish shot Bob posted. Had the subject not been centered, that shot may also be over exposed.

Here's a chart on the DR exposure modes:

http://www.dpreview.com/reviews/canoneos30...ge6.asp#afmeter

"Partial" metering only use about 10% of the center of the frame so that would not have worked either. "Evaluative" may have worked, there's no detail discription of how that's done, but there's no way to get the camera to do that on manual exposure. I think centering the subject and hitting the flash exposure lock button and then reframe the photo would work. This is not desirable for shooting fish since the flash exposure lock fires the flash and is likely to spook the subject.

This is one example where the * button may come in handy. Frame Herb's smiling face in the center, fire the star button (*) to set the flash meter, then recompose and shoot.

That's the difference between "regular" TTL and digital types of TTL. The digital types set the flash power before the shutter opens, unlike film cameras...

Cheers
James

Actually, it doesn't always work, nor does it tell how it figures it out. If it doesn't work, and the user then adjusts it, it can then change it's calculation and negate your adjustment. Not that this matters much as no strobe does 3-D multi-sensor matrix yada, yada, yada.

I think some people are confused on how the camera and flash meters. Some have noted it correctly. These are two separate functions. The camera meters the ambient light exposure e.g. via spot, central or matrix (or evaluative if you prefer). The flash TTL works separately. Current Nikon TTL uses a five point system. So, although your camera may be in matrix metering mode, the flash TTL is looking at five points in the scene.

Just to add even more confusion, different models may handle compensation differently when dealing with exposure and flash compensation. My attention span is way too short to deal with it all. Hogan wrote a book. I haven't read it. We talked about it, but I can't even remember all the details. It was late. My brain was fried.

I love it when you talk dirty like that.

Wow, this thread really exploded in just a couple of days.

Regarding TTL, I have to say that with my D100/Aquatica housing, a housed SB80DX works extremely well in TTL for macro subjects and fish ID. I used manual exposure for years with the Nikonos V, but for close-up and macro, I did use TTL with the SB-105/SB-103 strobes and got pretty good results. The metering systems are so good with the current crop of DSLRs that TTL is no longer a joke, and I don't feel embarrassed to admit that I use TTL on most shots. I don't do a lot of wide angle, and I acknowledge that TTL is generally not as effective in wide angle.

Anyway, back to the original thread (which seems like a long time ago, but it only started yesterday). I hope someone does develop a DTTL underwater strobe for the D100. Until then, I love my housed SB80DX!

Jim

<!--QuoteBegin-jamesw+Jan 15 2004, 10:50 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (jamesw @ Jan 15 2004, 10:50 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> This is one example where the * button may come in handy.  Frame Herb's smiling face in the center, fire the star button (*) to set the flash meter, then recompose and shoot.

That's the difference between "regular" TTL and digital types of TTL.  The digital types set the flash power before the shutter opens, unlike film cameras...

[/quote]

:wink: Minolta 9000 circa 1985[/b]

Nice photograph, Bob.

My own experience with TTL goes back to the early 1970s when I had a Honeywell automatic flash, where the flash unit itself decided when enough light had reflected from the subject. It wasn't TTL, but it was a direct precursor to having a flash meter behind the camera lens. I don't know why Nikon (and others, I believe) decided to use a pre-flash TTL system, but I have to assume there are good reasons. In any case, the Nikon DTTL system appears to work well.

Frankly, I love technology if it allows me to spend more time with composition and creativity. I still have the option to use manual everything, but I usually prefer autofocus and exposure, with exposure compensation cranked in when I choose to.

But Jim where did you tie up that dinosaur prior to using that system.

Bob is trying to sell me a 14mm Nikon but I keep telling him I have Canon. Anyone else interested in one? The price is really reasonable

Hi all.

I have some experience now with eTTL underwater. As a Canon shooter who bravely/stupidly dives with his 10D in a EWA-Marine housing, I do at least have the advantage of using my 420EX in eTTL mode. (My setup got it's first real use underwater a couple of weeks ago during a week at Ningaloo Reef, and I've just been assessign the results in the past few days.)

Shooting with this combo, I found that eTTL worked well underwater, but flash and general exposure compensation were both very helpful/vital.

The best mode generally to shoot in was Av, which on Canon SLRs/DSLRs exposes the background for ambient light, and uses ETTL to correctly expose the foreground. You can thus adjust foreground/subject exposure with flash exposure compensation, and background exposure with general exposure compensation, to get the balance you desire.

Manual mode works bst for macro, as you can control and use large depth of field (shutter speed in Av would be too slow).

So the eTTL definetly works, but I'd always want the ability to tweak my exposure settings as above. It's vital above water. and I think even more so underwater.

If 300D+Aquatica had a mode of flash exposure compensation, it would be great. If there's no means of flash exposure compensation, eTTL functionality would be cripppled (in either Av or M, your shutter speed and aperture don't affect the foreground subject flash exposure - ie., you're completely relying on the automatic flash exposure which like all automatic exposure systems will sometimes be wrong).

Despite the above comments, I'm very excited about Aquatica's development. Good work, chaps!

I found more info on the Canon eTTL.

http://doug.kerr.home.att.net/pumpkin/300D_metering_DAK.pdf

It's too bad they don't include this in the manual. Based on this, I think eTTL would have worked on my blown out photo had I used the 7 point focus and let the camera select the focus point, which I think it would have done correctly. I or rather my cousin who took the picture following my instructions used center point focus, foucs locked on me and reframed the shot. Too much thinking.

EXCUSE ME???
:angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire:

How reasonable?